TY - JOUR
T1 - Targeting the pedunculopontine nucleus
T2 - A new neurophysiological method based on somatosensory evoked potentials to calculate the distance of the deep brain stimulation lead from the Obex
AU - Insola, Angelo
AU - Valeriani, Massimiliano
AU - Mazzone, Paolo
PY - 2012/9
Y1 - 2012/9
N2 - BACKGROUND:: Pedunculopontine tegmental nucleus (PPTg) deep brain stimulation (DBS) has been used in patients with Parkinson disease. OBJECTIVE:: To verify the position of the DBS lead within the pons during PPTg targeting. METHODS:: In 10 Parkinson disease patients undergoing electrode implantation in the PPTg, somatosensory evoked potentials were recorded after median nerve stimulation from the 4 DBS electrode contacts and from 2 scalp leads placed in the frontal and parietal regions. RESULTS:: The DBS electrode recorded a P16 potential (latency at contact 0, 16.33 ± 0.76 ms). There was a P16 latency shift of 0.18 ± 0.07 ms from contact 0 (lower) to contact 3 (upper). The scalp electrodes recorded the P14 far-field response (latency, 15.44 ± 0.63 ms) and the cortical N20 potential (latency, 21.58 ± 1.42 ms). The P16 potentials recorded by the intracranial electrode contacts are generated by the volley traveling along the medial lemniscus, whereas the scalp P14 potential represents a far-field response generated at the Obex level. Considering that the distance between the electrode contacts 0 and 3 is 6 mm, the distance of the electrode contact 0 from the Obex (ΔObex) was calculated by the equation: ΔObex = 6 × Δlatency P14- PPTg0/Δlatency PPTg0-PPTg3. The Obex-to-brainstem electrode distance obtained by the neurophysiological method confirmed that the electrode was located within the pons in all patients. Moreover, this distance was very similar to that issued from the individual brain magnetic resonance imaging. CONCLUSION:: Somatosensory evoked potentials may be a helpful tool for calculating the macroelectrode position within the pons during PPTg targeting.
AB - BACKGROUND:: Pedunculopontine tegmental nucleus (PPTg) deep brain stimulation (DBS) has been used in patients with Parkinson disease. OBJECTIVE:: To verify the position of the DBS lead within the pons during PPTg targeting. METHODS:: In 10 Parkinson disease patients undergoing electrode implantation in the PPTg, somatosensory evoked potentials were recorded after median nerve stimulation from the 4 DBS electrode contacts and from 2 scalp leads placed in the frontal and parietal regions. RESULTS:: The DBS electrode recorded a P16 potential (latency at contact 0, 16.33 ± 0.76 ms). There was a P16 latency shift of 0.18 ± 0.07 ms from contact 0 (lower) to contact 3 (upper). The scalp electrodes recorded the P14 far-field response (latency, 15.44 ± 0.63 ms) and the cortical N20 potential (latency, 21.58 ± 1.42 ms). The P16 potentials recorded by the intracranial electrode contacts are generated by the volley traveling along the medial lemniscus, whereas the scalp P14 potential represents a far-field response generated at the Obex level. Considering that the distance between the electrode contacts 0 and 3 is 6 mm, the distance of the electrode contact 0 from the Obex (ΔObex) was calculated by the equation: ΔObex = 6 × Δlatency P14- PPTg0/Δlatency PPTg0-PPTg3. The Obex-to-brainstem electrode distance obtained by the neurophysiological method confirmed that the electrode was located within the pons in all patients. Moreover, this distance was very similar to that issued from the individual brain magnetic resonance imaging. CONCLUSION:: Somatosensory evoked potentials may be a helpful tool for calculating the macroelectrode position within the pons during PPTg targeting.
KW - Deep brain stimulation
KW - Medial lemniscus
KW - Pedunculopontine tegmental nucleus
KW - Pons
KW - Somatosensory evoked potential
UR - http://www.scopus.com/inward/record.url?scp=84865582788&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865582788&partnerID=8YFLogxK
U2 - 10.1227/NEU.0b013e318249c726
DO - 10.1227/NEU.0b013e318249c726
M3 - Article
C2 - 22899489
AN - SCOPUS:84865582788
VL - 71
JO - Neurosurgery
JF - Neurosurgery
SN - 0148-396X
IS - SUPPL.1
ER -